4 kV insulated gate controlled thyristor with low on-state voltage drop

A novel Insulated Gate Controlled Thyristor (IGCT) is described. The IGCT has a MOSFET that controls the thyristor current, and a thyristor with floating p-base for a low on-state voltage drop. The 4 kV IGCT is fabricated using optimized field limiting rings and field plates, and shows a very low on-state voltage drop of 4.4 V, while that of a 4 kV IGRT is 5.6 V. However, the maximum controllable current of the IGCT is lower than that of the IGBT. The low on-state voltage drop and a high maximum controllable current have been accomplished by optimizing the p-base structure.